# num = input("请输入一个数字")
# print("num 是小于30的数字"if int(num)<30 else "num是大于30的数字")

score = int(input("请输入一个分数:"))
# grade = ""
#
# if score<60:
#     grade = "不及格"
# elif 60<=score<80:
#     grade="及格"
# elif 80<score<90:
#     grade = "良好"
# elif 90 < score < 100:
#     grade = "优秀"
# print("分数是{0},等级是{1}".format(score,grade))

#测试选择结构的嵌套
# if score>100 or score<0:
#     grade="A"
# elif score>=80:
#     grade="B"
# elif score>=70:
#     grade="C"
# elif score>=60:
#     grade="D"
# else:
#     grade="E"

degree = "ABCDE"
num = 0
if score > 100 or score < 0:
    print("请输入一个0-100的分数")
else:
    num = score//10
    if num < 6: num = 5
    print(degree[9-num])
    print("分数是{0},等级是{1}".format(score,degree[9-num]))


